fix(translators): ameliorer le respect des formats de fichiers pour Excel, PowerPoint et PDF

- Excel: elargissement intelligent des colonnes pour le texte etendu et alignement RTL des cellules

- PowerPoint: retour a la ligne et auto-fit anti-debordement, colonnes de tableaux en RTL

- PDF: protection multi-colonnes pour eviter les chevauchements et formatage hebreu

- Tests: validation de non-regression pour tous les formats

tests/test_translators/test_rtl_layout.py

@@ -1225,3 +1225,42 @@ class TestLtrNormalization:
         assert "1." in lines[0] or "1" in lines[0]
         # Must not contain overflow marker
         assert "[translation overflow]" not in " ".join(lines)
+
+    def test_pdf_multicolumn_protection(self, tmp_path):
+        """Tier 1 expansion on a left column must not expand past the right column."""
+        import fitz
+
+        src = tmp_path / "src_cols.pdf"
+        doc = fitz.open()
+        page = doc.new_page(width=600, height=400)
+        # Left column at x=50..250, right column at x=300..500
+        page.insert_textbox(fitz.Rect(50, 50, 250, 100), "Titre gauche", fontsize=14, fontname="helv")
+        page.insert_textbox(fitz.Rect(300, 50, 500, 100), "Titre droite", fontsize=14, fontname="helv")
+        doc.save(str(src))
+        doc.close()
+
+        translator = PDFTranslator(
+            provider=MockTranslationProvider({
+                "Titre gauche": "A very long left heading translation that requires more width",
+                "Titre droite": "Right heading",
+            })
+        )
+        out = tmp_path / "out_cols.pdf"
+        translator.translate_file(src, out, "en")
+
+        doc2 = fitz.open(str(out))
+        blocks = doc2[0].get_text("blocks")
+        doc2.close()
+
+        left_blocks = [b for b in blocks if "left heading" in b[4]]
+        if left_blocks:
+            # The left block must NOT cross the start of the right column (x=300)
+            assert left_blocks[0][2] <= 300.0
+
+    def test_pdf_hebrew_formatting(self):
+        """Hebrew text must be visually formatted without Arabic cursive reshaping."""
+        from translators.pdf_translator import _shape_rtl_multiline
+        hebrew_text = "שלום עולם"
+        res = _shape_rtl_multiline(hebrew_text, max_width=200, fontsize=12)
+        assert res is not None
+        assert len(res) > 0